<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框</title>
    <style>
        .one{
            /*把4个边框 按照3要素进行拆分,分别设置*/
            border: 1px dashed red;/*可以一起写*/
            border-width: 10px 20px;
            border-style: dotted solid dashed;
            border-color:red blue yellow green;
        }
        .two{
            border-bottom: 5px solid red;
            border-top: 25px dashed blue;
            border-left: 15px dotted green;
            border-right: 35px double yellow;
        }
        .three {
            width: 0px;
            height: 0px;
            border: 50px solid white;
            border-top: 50px solid green;
            border-bottom: none;
        }
        /*边框有三要素:粗细,线性,颜色 只有颜色可以不写,默认是黑色  剩下的不写,边框无法显示*/
    </style>
</head>
<body>
<div class="one">老骥伏枥</div>
<div class="two">志在千里</div>
<div class="three">jkhdfdflak</div>

</body>
</html>